Is the 17-85 IS really that bad?

This lens has gotten many less good critics on reviews and many people are warning about not getting one. They say that the lens is dramatically soft, especially at 24mm wide open, and stopping down the aperture doesn't help much either. But is it really that bad? It costs around $425 here in Norway brand new on sale. I'm mostly interested in the IS, but if the optical quality is terrible, I guess I have to look elsewhere for a general purpose lens to the 50D.

Some have stated that the 18-55 II is better in general optical quality and the 18-55 IS just beats it with a huge margin.